You're going to hit a wall with every ISP in the US and any country whose major telecos don't give a shit.

Fundamentally, why do they have to support ipv6? Especially when they have monopoly power over their customers? Its not like the customers can see the difference, and if a website doesn't work for a network of millions because the site v6 only the only loser is the website.

I'd be surprised if we hit 15% this year. Web services are doing a good job supporting v6, but now you have to get all ISPs to do it as well, and those ISPs are always ranked as some of the most consumer unfriendly companies in a lot of countries because they have no market pressure to improve or serve their customers well.